Stormy Weather: Weather Service Predicts Active Hurricane Season

Forecasters call for more than 11 tropical cyclones

May 30, 2008

NASA

The U.S. National Weather Service Climate Prediction Center forecasts six to nine hurricanes—including as many as five major hurricanes with wind speeds above 111 miles (179 kilometers) per hour—this six-month season in the Atlantic, which officially begins on Sunday and ends November 30. Independent experts at Colorado State University in Fort Collins foresee much the same, making this a more active year than most for tropical cyclones in the Atlantic and Caribbean.

The total prediction calls for as many as 16 "named" storms, those whose winds reach more than 74 miles (119 kilometers) per hour. If one is born in the Atlantic Ocean or east of the international date line in the Pacific, it is called a hurricane; in the northwest Pacific, a typhoon; in the southwest Pacific and southeastern Indian oceans, such a storm is dubbed a severe tropical cyclone; in the north Indian, a severe cyclonic storm; and in the southwest Indian, a tropical cyclone. By any name, one of these storms can carry as much energy as 10,000 nuclear bombs—making them nature's most destructive meteorologic phenomenon.

These tropical cyclones typically begin to form in the Northern Hemisphere this time of year, as ocean waters warm, but do not reach their peak until August and September.

The accuracy of such forecasts is up in the air. The predictions are based on a continuing cool pattern in the Pacific Ocean, warmer waters in the Atlantic and the continuation of a trend for strong storm seasons in a climatic pattern that plays out over decades. But those trends also led to a prediction for an active season last year, which instead saw only six as opposed to the predicted seven to 10 hurricanes.

But 2007 did see two category 5 hurricanes—Felix and Dennis, whose winds reached more than 155 miles (250 kilometers) per hour—as well as storms that formed both before the official beginning of the season and after it closed on November 30. Tropical Storm Olga formed on December 11 last year. And Tropical Storm Alma has already kicked off the eastern Pacific hurricane season (which began on May 15) by lashing Nicaragua.